If you've ever heard that menopause hormone therapy "causes cancer," you're not alone: it's one of the most persistently distorted pieces of medical information of the past 20 years. It stems from a specific study, halted in an emergency in 2002, whose results were misinterpreted and poorly communicated from the start.

What this article explains: what that study actually showed, why it doesn't directly apply to French practice, what HRT actually looks like today, who it's not recommended for, and who can prescribe it today.

1- The WHI study (2002): what it actually showed

In July 2002, the American Women's Health Initiative (WHI) study was halted early and published in a rush. Its headline message, widely picked up by the press: HRT would increase the risk of breast cancer, stroke, and venous thrombosis. The immediate result: HRT prescriptions collapsed in France, as in the rest of the world.

But this study had several major methodological limitations, since identified by the scientific community:

• A population that was too old: participants were 63 years old on average, and many had been menopausal for more than 10 years. Yet when you start HRT fundamentally changes the picture (see the next section)
• Molecules different from French practice: the study used conjugated equine estrogens combined with a synthetic progestin, molecules rarely or no longer used in France today
• Oral route only, whereas the transdermal route (gel, patch), standard in France, has a very different cardiovascular risk profile
• A single dose for all participants, with no individual adjustment

The shared conclusion among French medical societies today: the 2002 reaction was disproportionate compared to what the data actually showed.

2- What the reanalyses changed: the "therapeutic window"

Since 2002, the WHI data has been reanalyzed taking into account participants' age and the time since their menopause. The conclusions are clear:

• Women who start HRT within 10 years of their menopause (or before age 60) have a favorable benefit-risk profile: bone benefits, likely cardiovascular benefits, symptom improvement
• Those who start it later have a less favorable profile, particularly on the cardiovascular side

This principle now has a name: the "therapeutic window." The effectiveness and safety of HRT largely depend on when it's started, not just on whether it's taken at all.

3- The French difference: different molecules, different risks

French practice has never relied on the same molecules tested by the WHI. Women in France on HRT most often receive:

• 17β-estradiol as a gel or patch (transdermal route): no demonstrated thromboembolic risk, unlike the oral route
• Micronized progesterone or dydrogesterone: no demonstrated increase in thromboembolic risk, and a more favorable breast risk profile than the synthetic progestins used in the American study

This is the central argument behind the French rehabilitation of HRT: women followed in France have never been exposed to the molecules behind the 2002 alert.

4- What HRT actually looks like today

Many people still picture HRT as a single hormone pill taken every day: an image inherited from 1990s United States practice, which is what the WHI study was based on. Current French practice is very different: HRT is almost always two separate products, taken separately.

Estrogen, applied to the skin: the most common form in France is transdermal gel, applied each morning to the skin (thigh, abdomen, or arm) with a dosing applicator, a gesture that takes a few seconds, similar to applying a cream. It also comes as a patch, stuck to the skin and changed every 48 to 72 hours depending on the product. Oral estrogen tablets still exist, but they've become secondary in France since the CNGOF/GEMVI and the HAS started recommending the transdermal route, which avoids first-pass liver metabolism and carries a lower cardiovascular and thromboembolic risk.

Micronized progesterone, as an oral tablet in the evening: taken at bedtime, often for around 14 days a month in people who haven't had a hysterectomy. It can also be used vaginally in case of drowsiness, a common side effect of the oral route.

Special case: people with a levonorgestrel IUD can use it as the progestin component and only need to add estrogen via the skin.

5- Current guidelines: CNGOF 2021 and HAS 2025

The CNGOF (French National College of Gynecologists and Obstetricians) and GEMVI published clinical practice guidelines in 2021 that set out a clear framework:

• HRT is indicated when menopause symptoms affect quality of life, after an individual assessment of the benefit-risk balance
• The recommended molecules are transdermal estradiol combined with micronized progesterone or dydrogesterone
• It can be started as early as perimenopause in symptomatic women, without waiting for the 12 months of amenorrhea that define menopause
• The decision is made jointly with the doctor, with at least an annual reassessment

In 2025, the Haute Autorité de Santé (French National Authority for Health) published its first complete reassessment of HRT in 11 years. It confirms HRT's status as the most effective treatment for menopause symptoms, and the only one reimbursed for this indication. It rules out certain synthetic progestins (associated with an increased risk of meningioma) as well as tibolone (unfavorable cardiovascular profile), and confirms the preference for the transdermal route over the oral route. The risk of breast cancer, however, remains real: it must be factored into the shared decision, without being minimized or overdramatized.

6- Who HRT is not recommended for

HRT isn't suited to every situation. Some contraindications are absolute, others relative, meaning they require a more in-depth individual assessment without automatically ruling out treatment.

Contraindications generally considered absolute:

• Personal history of breast cancer (regardless of hormone receptor status, invasive or in situ)
• History of endometrial cancer
• History of venous thromboembolism (phlebitis, pulmonary embolism) or known thrombophilic disorder
• Recent history of heart attack or stroke
• Severe active liver disease
• Unexplained genital bleeding, which must be investigated before any HRT

Situations that call for a case-by-case assessment, without being automatic contraindications: family history of breast cancer, migraine with aura, high blood pressure, diabetes, smoking. The CNGOF and GEMVI even note that for certain people with a history of thrombosis, the combination of transdermal estradiol and micronized progesterone can be discussed in specific cases, despite a contraindication listed in the drug package inserts.

7- Who can prescribe HRT in France today

Today, HRT can be prescribed by a gynecologist or a general practitioner. In practice, few general practitioners do, often out of unfamiliarity or caution inherited from the 2002 crisis.

Midwives cannot yet prescribe HRT for menopause. That could change: a parliamentary report submitted to the government on April 9, 2025 by MP Stéphanie Rist proposes allowing midwives to prescribe it for non-complex cases, subject to training requirements and within a coordinated care pathway. The measure is supported by the government, but its implementation still depends on several regulatory steps: it is not yet in effect.

This report starts from a clear finding: only 2.5% of menopausal women in France currently use HRT. Under-prescription is now recognized as a public health issue in its own right.

In summary

• The 2002 WHI study showed real risks, but in a population and with molecules not representative of current French practice
• When you start HRT profoundly changes the benefit-risk balance (the "therapeutic window")
• The molecules used in France (transdermal estradiol, micronized progesterone) have a more favorable risk profile
• The risk of breast cancer is real and must be discussed, without minimizing or overdramatizing it
• HRT isn't a single pill: it's most often a gel or patch of estrogen in the morning, and micronized progesterone in the evening
• HRT isn't suited to everyone: certain histories (breast cancer, thrombosis, stroke...) are contraindications; only a doctor can assess your individual situation
• Only gynecologists and general practitioners can prescribe HRT in France today; an extension to midwives is under consideration

This topic is part of a series of articles on the hormonal transition. Before starting HRT, it can help to understand which hormones actually change in perimenopause and whether a blood test is useful in your case, often one of the first questions asked in consultation. If you're already on HRT and wondering when and how to stop, our article on what actually happens when you stop HRT answers that question. And if you're still hesitant to bring it up with your doctor, our complete list of menopause symptoms will help you name precisely what you're feeling. If your cycles become unpredictable in the meantime, a well-suited reusable protection can simplify day-to-day life. To lay the groundwork for the transition as a whole, you can read our article on the differences between premenopause, perimenopause, and menopause.

HRT is neither a miracle treatment nor a danger to avoid at all costs: it's a medical option, with real benefits and real risks, to be discussed case by case with a healthcare provider. Twenty years of misinformation won't be undone by a single article, but understanding where the controversy came from is a first step toward talking about it calmly again.